cod4 get punkbuster errors

I installed cod4, single player works fine, however playing multiplayer, punkbuster gives me 'unknown api function 131134' .I also installed cod5 and i get no errors from punkbuster!! (strange)
Anybody else getting punkbuster errors with cod4 or a possible fix??

NOw I installed COD5 and it works without problems.

Looking at the console when connecting, on cod5 it uses the path:-


COD4 uses:-

C:\Program Files\Activision\Call of Duty 4 - Modern Warfare\pb

Tried alot of things to get this to work but i'am running out of ideas,
I will test some more and update if i find a fix!!